A cure for the mice and "creepy crawlies" during outside building winter storage:

Take a couple of zip-lock bags and punch a bunch of holes in them with a hole punch. Next put a couple of handfuls of mothballs in each bag and close the zip-lock bag (Yes, mothballs).
Now take the bags and put them in various locations in your shed. A 10x16 shed would need 3 - 4 zip-lock bags. The mice and "creepy crawlies" don't like the smell and vacate, usually within a couple of days. You could also scatter the mothballs around the shed, but this is neater, and if you have a cat or dog you don't have to worry about them eating any of the mothballs.

I found out about this several years ago when I had my boat. The mice got in it over the winter and did a number on the wiring and upholstery. A friend told me about the mothballs, so I tried it. No mice.

Just make sure you air the shed out for a couple of hours in the spring.

This will also work for the UNOCCUPIED AREAS of your house (attic, possibly the basement if it is very infrequently used) to get rid of mice, etc.